There is provided a system of detecting mark-sense indicia wherein the images of a light source (26) and the region of sensitivity (122) of a light sensor are substantially coaxial, coplanar, and coextensive throughout the working depth of field (21). This system is insensitive to the laminate and the diffusion effects. A light source (26) is aimed at a beam splitter (15) that diverts a portion of the light beam (36) through optics (14) that focus the light on a reflective target (12) containing a bar code symbol (17) to be scanned. The reflected beam (38) is returned through the optics (14) and the beam splitter (15), and a portion of the reflected beam is conducted to a light sensor (24). In this manner, the light path from the source (26) to the optical sensor (24) is split twice by the beam splitter (15). The optics (14) are configured so that the light beams that define the field of illumination and the region of sensitivity and which pass between the optics (14) and the target (12) are congruent, having identical optical axes and angles of divergence (16, 18). The region of sensitivy is congruent with the field of illumination in any plane throughout the depth of field of the optics. Field stops (20, 22) may be optionally provided for the light source (26) and the light sensor (24) in order to better define the dimensions of the field of view and field of illumination.

Intimate source and detector and apparatus employing same

A compact objective lens with a diaphragm arranged behind the lens system suitable for use in very compact photographic cameras The objective lens comprises a plurality of components arranged in a triplet or a triplet type configuration and is capable of covering at least a 55 degree field of view

Compact objective lens system

A compact objective lens system with a diaphragm arranged in front of or preferably behind the lens system and suitable for use in compact photographic cameras. The objective lens comprises a plurality of components arranged in a triplet-type configuration that are capable of covering at least a 55 degree field of view and utilizes the locations of aperture stop, the lens bendings, and the size of lens elements, clear apertures of the lens element surfaces to enhance the lens system performance and to eliminate stray light problems.

Triplet-type lens for use in a compact photographic camera

A behind-stop Tesser type lens system comprising a first lens component of a positive meniscus lens of which a convex surface is faced to the object-side, a second lens component of biconcave lens, and a third lens component of a cemented doublet comprising a negative meniscus lens and a biconvex lens and so arranged as to be compact and provided with a favorable image forming ability.

Behind-stop Tesser type lens system

An improved tesser type objective lens system having a rear aperture stop with a relatively wide field angle of about 60° and an F-number of about F 2.8 is provided. The thickness of the second negative lens in the lens system is increased relative to the total axial distance of the lens system which permits the reduction of the Petzval sum while maintaining a balance correction of spherical aberration and coma.

Tamikazu Yamaguchi

Papers

Tesser type objective lens system having a rear aperture stop